Add initialization tasks and an optional splash screen to ASP.NET Core web applications.
Install-Package DotNetContrib.AspNetCore.Initialization -Prerelease
To add an initialization task, implement IInitializationTask and register it in your Startup.ConfigureServices():
public class SampleInitializationTask : IInitializationTask
{
public async Task InitializeAsync(InitializationContext context)
{
// When using splash screen, report status
context.Status.Message = "Reticulating splines...";
await Task.Delay(TimeSpan.FromSeconds(30));
}
}
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
// ...
services.AddInitializationTask<SampleInitializationTask>();
// ...
}
}Next, we will have to update our host to run initialization - either with o without a splash screen:
public class Program
{
private const bool UseLoadingScreen = true;
public static async Task Main(string[] args)
{
var host = CreateWebHostBuilder(args).Build();
if (UseLoadingScreen)
{
await host.InitializeWithSplashScreenAsync();
}
else
{
await host.InitializeAsync();
}
await host.RunAsync();
}
private static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>();
}Add a file splash.htm in your wwwroot. Insert the string {InitializationContext.Status.Message} to render a splash message.
Sample splash.htm:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Loading...</title>
<style>
body { font-family: "Helvetica Neue", Helvetica, Arial, sans-serif }
</style>
<script>
setTimeout(function() {
location.reload(true);
}, 2500);
</script>
</head>
<body>
<div style="text-align: center;">
<img src="loading.svg" />
</div>
<div style="text-align: center;">
<h1>Loading...</h1>
<h2>{InitializationContext.Status.Message}</h2>
</div>
</body>
</html>